Effect Of Organic Manure On Activity Of Soil Microorganism, Yield And Quality Of Flue-cured Tobacco

Tobacco is one of the most important economical crops in China. The yield and quality of tobacco is subjected to manure fertilizers, tobacco varieties, soil fertility, climatic conditions, planting and curing technique etc. and among these all, manure fertilizer is the dominant factor which can regulate and promote the growth of the tobacco plants, improve soil fertility and enhance yield and quality of tobacco leaf. Application of organic manure with chemical fertilizer is the traditional mode of tobacco cultivation, so it is necessary to be studied. This study was carried out on the long-term manure experiment base, in Yunnan academy of tobacco agricultural sciences. Five different treatments were studied in which soil received:1. rapeseed cake,2. pig dung,3. straw (wheat),4. common vetch (green manure) and 5. chemic fertilizer (CK). In order to know the relation between different fertilizers and productivity of the tobacco, the effects of organic manure on activity of living organisms in soil, yield and quality of flue-cured tobacco were studied through three years field experiments (2007-2009). The experiment can provide scientific basis for rational fertilization and sustainable utilization of tobacco soil. Following are the main results:1. After the organic manure and chemical fertilizer application, the soil organic matter content showed a remarkable increase, especially straw and common vetch treatments had the most obvious effects. Organic manure increased the soil available K (except pig dung) and soil available P significantly. However, the soil bulk density was not significantly affected by the application of rapeseed cake, pig dung, straw, common vetch and chemic fertilizer, it varied between 1.2698-1.3748g/cm3.2. Compared with chemical fertilizer, rapeseed cake, pig dung, straw and common vetch enhanced the number of some beneficial microorganism in different extent. The quantities of fungi, silicate bacteria, organic and inorganic phosphorous bacteria were the highest in common vetch treatment, while pig dung treatment took second place and rapeseed cake treatment was close to straw.3. Organic manure improved the activity of soil phosphatase, urease and invertase in different degree and by pig dung application; the acid phosphatase activity was 3.4%-26.1% higher than ABSTRACTchemical fertilizer treatment. The alkaline phosphatase activity in organic manure treatments (exceptcommon vetch) increased by 6.3%～17.6%, and the neutral phosphatase activity in organic manuretreatments was 1.4～2.4 times of chemic fertilizer treatment, so in ranking acid phosphatase activity> alkaline phosphatase activity> neutral phosphatase activity. In addition common vetch, rapeseedcake, pig dung and straw significantly increased urease activity i.e.27.4%～88.1%. Invertase activityin straw and rapeseed cake treatment was 38.2% and 20.7% higher respectively, than chemicalfertilizer treatment but there was no significant difference among pig dung, common vetch andchemical fertilizer. Urease and invertase activity in common vetch treatment was least affected whilein straw treatment it had a maximal increase slope. 4. Organic manure improved the tobacco plant height, number of useful leaves, leaf area indexand single leaf weight compared with chemical fertilizer treatment. Generally the tobacco agronomiccharacteristics in organic manure treatments were similar to chemical fertilizer treatment fromtransplant to 45 days but after 75 days, the agronomic characteristics in chemical fertilizer werelower than that in organic manure(except the number of useful leaves between pig dung andchemical fertilizer). Compared to chemical fertilizer treatment the tobacco plant height in organicmanure treatments was increased by 1.6%～10.5%; the number of useful leaves was 10% higher(except pig dung) and the leaf area index increased by 8.8%～15.3%. At the time of harvest singleleaf weight in organic manure treatment was increased than that in chemical fertilizer treatment, inupper leaves it increased by 15.4%～68.9% and in lower leaves it increased by 2.02%～2.77% while itincreased by 14.3% in middle leaves of pig dung treatment, but in rapeseed cake, straw and commonvetch was lower than chemic fertilizer. Tobacco plant height, the number of useful leaves and theleaf area index in the four kinds of organic manure treatments were not same. The single leaf weightof upper leaves in pig dung treatment was significantly higher than rapeseed cake, straw andcommon vetch and single leaf weight of middle leaves was significantly higher than rapeseed cakeand straw, but was similar as common vetch, while in lower leaves it was different significantly indifferent organic manure treatments. 5. The rapeseed cake, pig dung, straw and common vetch treatments trend to increase the yieldand output value of flue-cured tobacco. Compared with chemical fertilizer treatment, yield per mu offlue-cured was 7.36%～21.4% higher than organic manure treatments. Output value per mu ofrapeseed cake, pig dung and straw was increased by 8.9% to 11.4%, while in common vetch it wasdecreased by 3.4%. The proportion of high grade cured leaves and high plus middle grade curedleaves and average price in straw treatment were the highest, so proportion of high plus middlegrades cured leaves in straw>rapeseed cake>chemic fertilizer>pig dung>common vetch. Andaverage price in straw>chemic fertilizer>rapeseed cake>pig dung>common vetch. 6. The quantity of total sugar and reducing sugar was higher in middle leaves compared to upside and downside leaves. Compare with chemical fertilizer, in organic manure treatments (except rapeseed cake treatment), when total sugar and reducing sugar content was increased in the downside leaves, it was significantly decreased in the upside leaves. The total sugar and reducing sugar content of the middle leaves in all five treatments was higher than the range of high quality tobacco, while it was within the normal range.7. Upper leaves had higher total nitrogen, nicotine and protein content than middle and lower leaves. Compared with chemical fertilizer, organic manure treatments improved total nitrogen, nicotine and protein content of the upper leaves. The leaf total nitrogen content of different treatments amplitude ranged from 1.47% to 2.18%, and leaf nicotine content ranged from 1.56% to 3.06%, which ranges to that of high quality tobacco, except upper leaves in common vetch treatment and middle leaves in pig dung treatment. Organic manure had little effect on the protein content of middle leaves and lower leaves.8. Chlorine content of tobacco had lower. Potassium content of upside leaf ranged from 1.16% to 1.30%, which of middle leaf ranged from 1.25% to 1.81%, and that of downside leaf between 1.60%～1.93%. Potassium content trend to decrease while leaf position raised, as downside leaf> middle leaf> upside leaf. Compared with chemic fertilizer, chlorine and potassium content of tobacco leaf were different in different organic manure treatment.8. Potassium content of the upper leaves ranged from 1.16% to 1.30%, in middle leaves it ranged from 1.25% to 1.81%, and in lower leaves it was between 1.60%～1.93%, so simply potassium content can be ranked as in lower leaves> middle leaves> upper leaves. Chlorine content of tobacco was lower in all the treatments. Chlorine and potassium content of tobacco leaves was different in different organic manure treatment when compared with chemical fertilizer.9. The N-nicotine ratio in tobacco leaf trend to decrease with raising leaf position (except pig dung treatment). The sugar-nicotine ratio and schmuck's value was ranked as in middle leaves> lower leaves> upper leaves. When compared with chemical fertilizer, sugar-nicotine ratio of upper leaves significantly decreased (i.e.10) in rapeseed cake, pig dung and straw treatments, so improved the quality of upper leaves. The N-nicotine ratio of upper leaves in common vetch treatment had great difference from high quality tobacco, but it ranged from 0.71 to 1.06 in all other treatments, which was nearly in range of high quality tobacco. The schmuck's value ranged from 2.54 to 4.56. In addition K-Cl ratio was less than 4 in the upper leaves in common vetch treatment, and in the rest it was more than 4. Compared with chemic fertilizer, the K-Cl ratio decreased in rapeseed cake, pig dung and straw treatment and trend to high quality tobacco. Overall, with the application of rapeseed cake, pig dung and straw, the harmony of chemical components was reinforced, and pig dung had the best effect.